The Moat Pit

Overview

The Moat Pit at Culross, built around 1590 by Sir George Bruce, is the world's first known example of undersea coal mining -- a stone tower rising from the Firth of Forth, worked for 35 years until destroyed by the Great Storm of 1625.

History

The Moat Pit was built around 1590 at Culross, Fife, by Sir George Bruce of Carnock, the centrepiece of a coal-mining and salt-panning enterprise his family developed between 1575 and 1676, later continued by his son George Bruce II and grandsons Edward and Alexander Bruce, successive Earls of Kincardine. The pit took the form of a circular stone tower some 15.54 metres in diameter at its base, its shaft 4.2 metres across, buttressed by three concentric retaining walls -- the innermost gap packed with puddled clay against seawater intrusion, the outer void with rough stone for protection. The shaft descended around 40 feet (12 metres) to reach the Upper Hirst coal seam, with underground workings extending more than an English mile beneath the sea. Drainage relied on an 'Egyptian Wheel', a horse-powered chain of 36 buckets that lifted water from a depth of around 40 fathoms (73 metres). The pit and its wider enterprise -- said to represent Scotland's first integrated industrial complex, combining coal, salt extraction, metalworking and glass manufacture -- attracted notable visitors, among them King James VI and I, who is said to have cried 'Treason' on emerging from the pit surrounded by open sea, and the poets John Taylor and Ben Jonson. John Taylor's own 1618 account records the pit as having then operated for some 28-29 years. The Moat Pit was destroyed after roughly 35 years of working when the Great Storm of 30 March 1625 overwhelmed and flooded it.

Geology

Worked the Upper Hirst coal seam beneath the Firth of Forth.

Workings

A stone tower shaft, 15.54 m in diameter at its base, buttressed by concentric retaining walls packed with clay against seawater; drained by a horse-powered 'Egyptian Wheel' of 36 buckets; underground workings extended more than a mile beneath the Firth of Forth.

Closure

Destroyed by the Great Storm of 30 March 1625, which overwhelmed and flooded the workings after roughly 35 years of operation.

What remains

Minimal evidence survives above the foreshore; at low tide, stone foundations and the infilled shaft can still be made out around 400 metres south of the high-water mark near Blairburn. A related shaft from the same enterprise, St Mungo's Pit, survives partially, largely filled, at Culross's football pitch.

Stone foundations and the infilled shaft, visible at low tide.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• The pit was a circular stone tower 15.54 metres in diameter at its base with a 4.2-metre shaft, buttressed by three concentric retaining walls, the innermost gap packed with puddled clay against seawater; it was drained by an 'Egyptian Wheel', a horse-powered chain of 36 buckets lifting water from around 40 fathoms. ¹
• The pit attracted notable visitors including King James VI and I, said to have cried 'Treason' on emerging from the pit surrounded by open sea, and the poets John Taylor and Ben Jonson; John Taylor's own 1618 account records the pit as having by then operated for 28-29 years. ¹
• The Moat Pit was destroyed by the Great Storm of 30 March 1625, which overwhelmed and flooded the workings after roughly 35 years of operation. ¹
• Canmore, the official database of Historic Environment Scotland, records the site as 'Culross, The Moat, Coal Shaft', independent confirmation of the site's location and status as a recognised heritage record. ²

Photographs & further reading

Sources

1. (secondary) The Moat Pit at Culross — Wikipedia
2. (primary) Culross, The Moat, Coal Shaft — Canmore (Historic Environment Scotland)

Record created: 2 September 2026 · Last researched: 2 September 2026